Muir Lindsey A, Nguyen Quynh G, Hauschka Stephen D, Chamberlain Jeffrey S
Program in Molecular and Cellular Biology, University of Washington ; Department of Neurology, University of Washington.
Department of Biochemistry, University of Washington.
Mol Ther Methods Clin Dev. 2014 Jun 25;1:14025. doi: 10.1038/mtm.2014.25.
Autologous dermal fibroblasts are promising candidates for enhancing muscle regeneration in Duchenne muscular dystrophy (DMD) due to their ease of isolation, immunological compatibility, and greater proliferative potential than DMD satellite cells. We previously showed that mouse fibroblasts, after MyoD-mediated myogenic reprogramming in vivo, engraft in skeletal muscle and supply dystrophin. Assessing the therapeutic utility of this system requires optimization of conversion and transplantation conditions and quantitation of engraftment so that these parameters can be correlated with possible functional improvements. Here we derived dermal fibroblasts from transgenic mice carrying mini-dystrophin, transduced them by lentivirus carrying tamoxifen-inducible MyoD, and characterized their myogenic and engraftment potential. After cell transplantation into muscles of immunocompetent dystrophic mice, tamoxifen treatment drove myogenic conversion and fusion into myofibers that expressed high levels of mini-dystrophin. Injecting 50,000 cells/microliter (1 × 10 total cells) resulted in a peak of ~600 mini-dystrophin positive myofibers in TA muscle single cross-sections. However, EDL muscles with up to 30% regional engraftment showed no functional improvements; similar limitations were obtained with whole muscle mononuclear cells. Despite the current lack of physiological improvement, this study suggests a viable initial strategy for using a patient-accessible dermal cell population to enhance skeletal muscle regeneration in DMD.
自体真皮成纤维细胞有望成为改善杜氏肌营养不良症（DMD）肌肉再生的候选细胞，因为它们易于分离、具有免疫相容性，且与DMD卫星细胞相比具有更强的增殖潜力。我们之前表明，小鼠成纤维细胞在体内经MyoD介导的肌源性重编程后，可植入骨骼肌并提供抗肌萎缩蛋白。评估该系统的治疗效用需要优化转化和移植条件，并对植入情况进行定量分析，以便将这些参数与可能的功能改善相关联。在此，我们从携带微型抗肌萎缩蛋白的转基因小鼠中获取真皮成纤维细胞，用携带他莫昔芬诱导型MyoD的慢病毒进行转导，并对其肌源性和植入潜力进行了表征。将细胞移植到具有免疫活性的营养不良小鼠的肌肉中后，他莫昔芬处理促使细胞发生肌源性转化并融合形成表达高水平微型抗肌萎缩蛋白的肌纤维。每微升注射50,000个细胞（共1×10个细胞），在TA肌单横切面上产生约600个微型抗肌萎缩蛋白阳性肌纤维的峰值。然而，区域植入率高达30%的EDL肌未显示出功能改善；全肌单核细胞移植也得到了类似的局限性结果。尽管目前缺乏生理功能改善，但本研究提出了一种可行的初始策略，即利用患者可获取的真皮细胞群体来增强DMD患者的骨骼肌再生。
